mirror of
https://gitlab.com/OpenMW/openmw.git
synced 2025-03-14 10:21:09 +00:00
utf8.codes
This commit is contained in:
parent
d9c102e14d
commit
6d02c31720
@ -22,6 +22,53 @@ namespace
|
||||
return integer;
|
||||
}
|
||||
|
||||
// returns: first - character pos in bytes, second - character codepoint
|
||||
static std::pair<int64_t, int64_t> poscodes(const std::string_view& s, std::vector<int64_t>& pos_byte)
|
||||
{
|
||||
const int64_t pos = pos_byte.back() - 1;
|
||||
const unsigned char ch = static_cast<unsigned char>(s[pos]);
|
||||
int64_t codepoint = -1;
|
||||
size_t byteSize = 0;
|
||||
|
||||
if ((ch & 0b10000000) == 0)
|
||||
{
|
||||
codepoint = ch;
|
||||
byteSize = 1;
|
||||
}
|
||||
else if ((ch & 0b11100000) == 0b11000000)
|
||||
{
|
||||
codepoint = ch & 0b00011111;
|
||||
byteSize = 2;
|
||||
}
|
||||
else if ((ch & 0b11110000) == 0b11100000)
|
||||
{
|
||||
codepoint = ch & 0b00001111;
|
||||
byteSize = 3;
|
||||
}
|
||||
else if ((ch & 0b11111000) == 0b11110000)
|
||||
{
|
||||
codepoint = ch & 0b00000111;
|
||||
byteSize = 4;
|
||||
}
|
||||
|
||||
// construct codepoint for non-ascii
|
||||
for (size_t i = 1; i < byteSize; ++i)
|
||||
{
|
||||
// if not a continuation byte
|
||||
if ((pos + i) >= s.size() || (static_cast<unsigned char>(s[pos + i]) & 0b11000000) != 0b10000000)
|
||||
{
|
||||
return std::make_pair(0, -1);
|
||||
}
|
||||
codepoint = (codepoint << 6) | (static_cast<unsigned char>(s[pos + i]) & 0b00111111);
|
||||
}
|
||||
|
||||
std::pair<size_t, int64_t> res = std::make_pair(pos_byte.back(), codepoint);
|
||||
|
||||
pos_byte.push_back(pos_byte.back() + byteSize); /* the next character (if exists) starts at this byte */
|
||||
|
||||
return res;
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
namespace LuaUtf8
|
||||
@ -45,6 +92,20 @@ namespace LuaUtf8
|
||||
}
|
||||
return result;
|
||||
};
|
||||
|
||||
utf8["codes"] = [pos_byte = std::vector<int64_t>{ 1 }](const std::string_view& s) {
|
||||
return sol::as_function([s, pos_byte]() mutable -> sol::optional<std::pair<int64_t, int64_t>> {
|
||||
if (pos_byte.back() <= static_cast<int64_t>(s.size()))
|
||||
{
|
||||
const auto pair = poscodes(s, pos_byte);
|
||||
if (pair.second == -1)
|
||||
throw std::runtime_error("Invalid UTF-8 code at position " + std::to_string(pos_byte.size()));
|
||||
|
||||
return pair;
|
||||
}
|
||||
return sol::nullopt;
|
||||
});
|
||||
};
|
||||
return utf8;
|
||||
}
|
||||
}
|
||||
|
Loading…
x
Reference in New Issue
Block a user